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That's an interesting question - if you have examples of some of the secondary keywords you're looking at, that would be helpful for comparison. There's a few things I would recommend. The first is rather than guessing or trying to search for the right keyword, analyze competitor domains or specific competitor URLs to see what they rank for. For example, here are 400+ keywords that https://www.coursera.org/learn/songwriting-lyrics is ranking for. That number of overall keywords will typically make up for low volume on some of them. The second thing is that lots of long tail searches, when combined, can produce meaningful traffic. So it is often worth testing out publishing a page on a keyword and seeing what type of traffic occurs naturally over 3-`12 months. 10 people who really really want a $10 or $100 solution to a problem and more valuable than 1,000 people not interested in buying anything. The third thing is that sometimes people aren't searching for a product, but, if you rank for another term they're interested in, you can make some sales by giving them something worth buying. "how to write a song" has 11.5k-30.3k searches per month - I'm not certain you can make 500 sales off of those types of volume ranges, but, you might be able to make 10-50 when you rank for a big head term, or lots of longer tail terms. This "rank for other stuff and then sell our product" approach may be what is working well for the competitors you mentioned. Finally - consider other types of queries that might make sense - 'music production classes" instead of "learn music productin online", for instance.